Field of the Invention
The present invention generally relates to an optical bonding apparatus, and more particularly, to an optical bonding apparatus with multiple layer structure, a method for producing the same and a touch sensitive display using the same.
Description of the Related Art
A liquid crystal display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly. Generally, an LCD apparatus includes a display substrate, a liquid crystal drive substrate and a liquid crystal apparatus sealed between the display side substrate and the liquid crystal drive side substrate. For the liquid crystal display apparatus, the display is carried out by electrically controlling the liquid crystal drive side substrate to change the amount of transmitted light from the light source.
The gap between the display side substrate and the liquid crystal drive side substrate is filled with LCs. As a result, the thickness of the gap is the same as the thickness of the liquid crystal layer.
The distance between the display side substrate and the liquid crystal drive side substrate may have inconsistencies. Such inconsistency will cause the existence of stress in the LCD when the LCs are sealed in the gap. The stress will lead to the variation of the thickness of the liquid crystal layer. As a result, a mura condition develops.
Mura is the phenomenon described as follows when an LCD is illuminated, an uneven color line or a color block may be appear on the LCD screen. The color line or the color block is yellow when the background is white, and the color line or the color block is white when the background is gray.
Generally, the LCD technology is combined with touch sensitive technology to provide easy input to a given system. A touch sensitive display device generally includes an LCD and a transparent touch panel placed thereon. The distance between the LCD and the touch panel can not be guaranteed to be even, which will amplify the stress, and at the same time increase the chance of mura condition.